TORQDEX // ELEC-01
Voltage Drop Calculator
Calculate how much voltage is being lost across an automotive circuit and what percentage of source voltage that represents.
INPUT DATA
RESULT
Enter the source voltage and measured voltage drop.
01 // WHAT THE RESULT MEANS
Why voltage drop matters
Voltage should do useful work
Voltage drop occurs whenever electrical resistance exists in a circuit. Some drop is normal, but excessive resistance in cables, terminals, grounds, connectors, or switches can prevent a component from receiving enough voltage to operate correctly.
Test the circuit under load
A voltage-drop test is most useful while the circuit is operating. A cable or connection may show continuity with no load and still develop excessive resistance when current flows through it.
Use specifications when available
The acceptable amount of voltage drop depends on the circuit and manufacturer specifications. The assessment shown here is a general guide, not a replacement for vehicle-specific service information.
FORMULA
Percentage voltage loss
(Voltage Drop ÷ Source Voltage) × 100
Example: 0.25 V ÷ 12.6 V × 100 = 1.98%